Hello Codeforces! This Saturday, the student final of BSUIR Open XIII will take place, accompanied by rounds Codeforces Round 1021 (Div. 1) and Codeforces Round 1021 (Div. 2) at Apr/26/2025 11:35 (Moscow time), featuring problems from this competition. Note the unusual time of the round.

This year, the problems for the rounds and the olympiad were prepared by teraqqq, FairyWinx, Kirill22, and wilcot. Each round will contain 6 problems, and you will have 3 hours to solve them. Notably, wilcot has been contributing problems to BSUIR Open for multiple years and has helped involve new authors in this event. We believe this effort has resulted in a diverse and exciting student final, part of which has been adapted into this Codeforces round.

We extend our special thanks to MikeMirzayanov, geranazavr555, and KAN for the fantastic Polygon and Codeforces platforms! We also thank:

• Artyom123 for coordinating the round and recruiting testers;
• arvindf232, A_G, N_z__, jtrh, __jk__, reirugan, and larush for testing the round;
• Golovanov399, SomethingNew, allvik66, golikovnik, and OG_Matveychick1 for testing the BSUIR Open problems;
• i_love_gold_and_nt and Gornak40 for their help in preparing the problem statements.